Valve assembly for introducing instruments into body cavities

ABSTRACT

A valve assembly is provided for permitting the introduction of a surgical instrument into a patient&#39;s body while providing a substantial seal about the instrument. The valve assembly includes a sealing gasket assembly providing a fluid tight seal before instrument insertion, and is configured and dimensioned for accommodating an instrument and providing a substantial fluid tight seal after insertion of an instrument. The valve assembly may further include a deformable sealing member having a substantially central aperture for accommodating the instrument. The sealing member provides a substantial seal about the instrument when the instrument is passed therethrough impeding the egress of fluids and gasses through the valve assembly.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 08/814,757,filed Mar. 7, 1997 now U.S. Pat. No. 6,569,120, which is acontinuation-in-part of application Ser. No. 07/873,416, filed Apr. 24,1992 ABN and application Ser. No. 07/781,063, filed Oct. 18, 1991 nowU.S. Pat. No. 5,203,773, the disclosures of which are herebyincorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to valve systems of the type adapted to allow theintroduction of a surgical instrument into a patient's body. Inparticular, the invention is applicable to a cannula assembly wherein acannula housing includes the valve assembly and the cannula is intendedfor insertion into a patient's body to sealingly accommodate aninstrument inserted through the cannula and valve.

2. Background of the Prior Art

In laparoscopic procedures surgery is performed in the interior of theabdomen through a small incision; in endoscopic procedures surgery isperformed in any hollow viscus of the body through narrow tubes orcannula inserted through a small entrance incision in the skin.Laparoscopic and endoscopic procedures generally require that anyinstrumentation inserted into the body be sealed, i.e. provisions mustbe made to ensure that gases do not enter or exit the body through theincision as, for example, in surgical procedures in which the surgicalregion is isufflated. Moreover, laparoscopic and endoscopic proceduresoften require the surgeon to act on organs, tissues, and vessels farremoved from the incision, thereby requiring that any instruments usedin such procedures be relatively long and narrow.

For such procedures, the introduction of a tube into certain anatomicalcavities such as the abdominal cavity is usually accomplished by use ofa trocar assembly comprised of a cannula assembly and an obturator. Thecannula assembly includes a cannula tube attached to a valve assemblywhich is adapted to maintain a seal across the opening of the cannulaassembly. Since the cannula tube is in direct communication with theinternal portion of the valve assembly, insertion of the cannula tubeinto an opening in the patient's body so as to reach the inner abdominalcavity must maintain a relatively gas-tight interface between theabdominal cavity and the outside atmosphere.

Since surgical procedures in the abdominal cavity of the body requireinsufflating gases to raise the cavity wall away from vital organs, theprocedure is usually initiated by use of a Verres needle through which agas such as CO₂ is introduced into the body cavity. Thereafter, thepointed obturator of the trocar assembly is inserted into the cannulaassembly and used to puncture the abdominal cavity wall. The gasprovides a slight pressure which raises the inner wall surface away fromthe vital organs thereby avoiding unnecessary contact with the organs bythe instruments inserted into the cannula. Following removal of theobturator, laparoscopic or endoscopic surgical instruments may then beinserted through the cannula assembly to perform surgery within theabdominal cavity.

In view of the need to prevent leakage of the insufflation gas from thecavity, the cannula is typically provided with a valve assembly whichpermits introduction of surgical instruments to provide selectivecommunication between the inner atmosphere of the cavity with theoutside atmosphere. In this regard, there have been a number of attemptsin the prior art to provide such a seal as part of the cannula assembly.

One form of cannula valve assembly includes a flapper valve which ispivotally mounted within the cannula assembly and is automaticallyopened by the obturator or other object when it is inserted into theproximal end of the cannula. Conventional flapper valves may also bemanually opened by pivoting a lever on the exterior of the housing. See,e.g., U.S. Pat. No. 4,943,280 to Lander. Trumpet valves are also known.

Other conventional cannula valve devices for accommodating surgicalinstruments include a single or plurality of flexible sealing members asshown, for example, in U.S. Pat. No. 4,655,752 to Honkanen et al., U.S.Pat. No. 4,909,798 to Fleischhacker, U.S. Pat. No. 4,673,393 to Suzukiet al., U.S. Pat. No. 4,610,665 to Matsumoto et al., and U.S. Pat. No.4,869,717 to Adair.

Further, typical hemostasis valve devices are shown, for example, inU.S. Pat. No. 5,041,095 to Littrell, and U.S. Pat. No. 5,000,745 toGuest et al.,

While attempts have been made to provide a valve assembly whichmaintains the integrity of the seal between the body cavity and theatmosphere outside the patient's body. Seal systems provided to datehave failed to address the full range of surgeons' needs, especiallywhen instruments varying in diameter are used. Specifically, sealingelements currently used may be damaged when an instrument, such as apointed obturator is passed therethrough. Moreover, present seal systemshave not provided adequate sealing about an instrument before and afteran instrument is passed therethrough. Also, existing seal systems havefailed to provide adequate sealing of a cannula, or a trocar assemblyhaving a cannula which accommodates instruments of varying diameters. Itis a further disadvantage of existing seal systems that adequate sealingis not provided in conjunction with a structure for holding a cannula ina desirable position in an incision with respect to a patient's body.

It would therefore be desirable to provide a valve assembly whichaddresses these shortcomings in the art by maintaining a substantiallyfluid tight seal between an internal portion of a patient's body and theoutside atmosphere during insertion and manipulation of a surgicalinstrument into the patient's body. Such an assembly may further providestabilization or lateral limitation of motion of an instrument passedtherethrough. Also, the valve assembly may inhibit fluids from exitingwith the instrument while being withdrawn, and the valve assembly mayinhibit contact with sealing structure. It is further desirable toprovide a valve assembly for use with a cannula or trocar assembly whichprovides substantial fluid and gas tight sealing before and after aninstrument is passed therethrough. It would also be desirable to providea cannula which maintains a predetermined position of a cannula ortrocar assembly in an incision.

The present invention provides a valve assembly which may beincorporated into a cannula assembly or utilized in combination with anytype of tubular member for providing access into the body of a patientwhile permitting introduction of instruments through the valve assemblyinto the body. The valve assembly includes a sealing gasket whichprovides a desirable seal about an instrument inserted through the valveassembly. The valve assembly may further provide stabilization of thecannula or limit lateral motion of the cannula when an instrument ispassed therethrough. Also, the valve assembly may include more than onesealing element providing improved sealing qualities under variedconditions. At all times, the surgeon maintains control over theinterface between the atmospheres within and without the patient's body.Moreover, the present invention makes it possible to introduceinstruments of varying sizes into the body and insures the maintenanceof a gas seal despite instrument manipulation therethrough.

SUMMARY OF THE INVENTION

A valve assembly is provided for permitting the introduction of asurgical instrument into a patient's body through a tube such as acannula. The valve assembly includes at least one sealing gasketconstructed of a flexible material and having a passageway. Thepassageway is substantially closed prior to insertion of an instrumentthrough the valve assembly forming a substantial gas tight seal. When aninstrument is inserted through the passageway of the valve assembly theflexible material defining the passageway resiliently engages an outersurface of the instrument in a substantially gas tight manner.

The sealing gasket may include sealing structure having first and secondoverlapping elements. The sealing gasket can be removably positioned ona frame or in a housing assembly such that the first and secondoverlapping elements are tensioned.

The valve assembly may further include sealing structure comprising athird element having a substantially central aperture. The third elementmay have a tapered portion and be constructed at least partially of aflexible material. The third element accommodates an instrument passedthrough its central aperture providing substantial sealing about theinstrument passed therethrough. A retainer structure inhibits contact bythe instrument with adjacent sealing structure such as, the first andsecond elements of the gasket assembly or the third element. Theretainer structure includes at least one movable portion and asubstantially central aperture for accommodating the instrument.

The valve assembly may further provide a sealing structure comprising afourth element for substantially removing fluids from the surface of aninstrument passed therethrough. The fourth element may include asubstantially central aperture defined by a deformable material suchthat the central aperture is capable of accommodating the instrument.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing features of the present invention will become more readilyapparent and will be understood by referring to the following detaileddescription of preferred embodiments of the invention, which aredescribed hereinbelow with reference to the drawings wherein:

FIG. 1 is an exploded perspective view of a cannula assemblyillustrating a valve assembly according to the present invention;

FIG. 2 is a perspective view illustrating a sealing gasket assemblyshown as part of the valve assembly illustrated in FIG. 1;

FIG. 3 is a cross-sectional view of the sealing gasket assembly takenalong line 3—3;

FIG. 4 is a perspective view of the sealing gasket assembly during theinsertion of an instrument;

FIG. 5 is an exploded perspective view of a cannula assemblyillustrating the valve assembly according to another embodiment of thepresent invention;

FIG. 6 is a front elevational view illustrating a rectangular retainerand a circular retainer in a coupled configuration;

FIG. 7 is an exploded perspective view illustrating the rectangularretainer and the circular retainer during the insertion of aninstrument;

FIG. 8 is a front elevational view of a foam block shown as part of thevalve assembly illustrated in FIG. 5; and

FIG. 9 is an exploded perspective view of a cannula assemblyillustrating the valve assembly according to another embodiment of thepresent invention.

FIG. 10 is an exploded perspective view illustrating a cannula and valveassembly according to the present invention;

FIG. 11 is an exploded perspective view illustrating a housing assemblyof the valve assembly shown in FIG. 10;

FIGS. 12, 13 and 14 are exploded perspective views of a cannula assemblyillustrating the valve assembly of FIG. 10 during the insertion of aninstrument;

FIG. 15 is an exploded perspective view illustrating a valve assemblyaccording to another embodiment of the present invention;

FIG. 16 is an exploded perspective view of a cannula assemblyillustrating the valve assembly of FIG. 15 during the withdrawal of aninstrument;

FIG. 17 is an exploded perspective view illustrating a cannula and valveassembly according to another embodiment of the present invention; and

FIGS. 18, 19 and 20 are exploded perspective views illustrating thecannula and valve assembly of FIG. 17 during the insertion of aninstrument.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention contemplates introduction into a patient's body ofall types of surgical instruments including, but not limited to clipappliers, lasers, photographic devices, graspers, scissors, tubes, andthe like. All of such objects are referred to herein as “instruments”.

Referring to the drawings, in which like reference numerals identifyidentical or similar elements, FIGS. 1—3 illustrate a preferredembodiment of a valve assembly 10. The valve assembly 10 is incorporatedinto a cannula valve housing 12 having an upper half 12 a and a lowerhalf 12 b attached at the proximal end of the cannula 14. The valveassembly 10 provides a substantial seal between a body cavity of apatient and the outside atmosphere before and after an instrument isinserted through the cannula valve housing 12. Moreover, each of thevalve assemblies of the present invention is capable of accommodatinginstruments of varying diameters, e.g., from 3 mm to 15 mm, by providinga gas tight seal with each instrument when inserted, and returning to afully sealed configuration upon removal of the instrument in the valveassembly. This flexibility of the present valve assembly greatlyfacilitates endoscopic surgery where a variety of instruments havingdiffering diameters are often needed during a single surgical procedure.

Referring to FIG. 1, the valve assembly 10 includes a first retainer 16at its proximal end and a second retainer 18 distal to the firstretainer 16 and proximal a bellows seal 20. The retainers 16, 18 arepreferably formed of a suitable synthetic resin or plastic, such aspolypropylene. The first and second retainers 16, 18 are essentiallyidentical and both preferably include generally rectangular plates 22having integrally molded circular body portions 24 extendingorthogonally from the rectangular plates 22. The body portion 16 mateswith the proximal side of the sealing gasket assembly 36.

Although the plates 22 are generally rectangular shaped in the preferredembodiments described herein and shown in the accompanying drawings, anyplate shape may be desirable, such as, for example circular shaped.Further, other geometric configurations of the body portion 24 may becontemplated or, for example, the body portion 24 itself may beeliminated by attaching the movable portions 26 (described below) to theplate 22.

As best seen in FIG. 6, preferably a plurality of triangularly shapedmovable portions 26 are divided by a series of slits 28 and are attachedto the perimeter 30 of the body portions 24 of the retainers 16, 18 byhinge regions 32. The slits 28 extend radially outward from centralaperture 34 of the retainers 16, 18.

A sealing gasket assembly 36 is distal to the first retainer 16 andpreferably includes identical first and second elements 38, 40 made of aflexible resilient material. Preferably, both the first and secondelements 38, 40 include a substantially circular body 42 having a wall44 defining a semi-circular opening 46. As shown in FIG. 3, the outerperimeter of the body includes a groove 48 defined by two ridges 50. Thegroove on the outer perimeter defines a ridge 52 on the innercircumference of the body 42.

Although the sealing gasket assembly includes a substantially circularbody as described in the preferred embodiments herein and illustrated inthe accompanying drawings, the sealing gasket assembly may include abody having a different geometric configuration, such as, for example, arectangular shape. Additionally, although sealing gasket assembly 36 isdescribed in the preferred embodiments herein as consisting of first andsecond elements 38, 40, it is also contemplated that first element 38may have a semicircular wall of similar configuration to wall 40 bondedto the circumference of first element 38 to create two overlappingmembers. This approach eliminates one structure from the overall valveassembly.

As shown in FIGS. 1 and 2, the first and second elements 38, 40cooperate by positioning the semi-circular opening 46 in each elementradially opposite each other. Thus, the second element 40 fits over thefirst element 38 in overlapping relation such that the wall 44 of thefirst element 38 covers the opening 46 in the second element 40, and thewall 44 of the second element 40 covers the opening 46 of the firstelement 38. Further, the ridge 52 on the inner circumference of thesecond element 40 mates with the groove 48 in the first element 38. Thesealing gasket assembly 36 provides a substantially fluid tight sealbefore instrument insertion.

The flexible material allows the sealing gasket assembly 36 toaccommodate instruments of varying sizes, e.g., diameters of from 3 mmto 15 mm. The sealing gasket assembly is preferably made of a flexiblematerial having a durometer in the range of 25-35, and most preferably adurometer of 30. As shown in FIG. 4, flexible resilient wallsaccommodate an instrument 37 by resiliently deforming to enable theinstrument 37 to pass therethrough. Upon removal of instrument 37,sealing gasket assembly 36 returns to its initial position, therebyreestablishing a substantially fluid tight seal. To facilitate andensure that the fluid tight seal is reestablished upon instrumentremoval, it is preferred that walls 44 be placed under tension, therebycreating a tautness which further biases walls 44 toward their initialoverlapping, abutting relation. This tension may be created by moldingelements 38 and 40 of a slightly smaller diameter than the matableportion of retainer 16, and then stretching elements 38 and 40 to matetherewith.

The bellows seal 20 is positioned distally adjacent the second retainer18 and is made of a suitable flexible resilient material. The bellowsseal 20 is preferably formed of an elastomeric material such as,preferably, natural rubber. The bellows seal 20 has a generally circularbody 54 and includes a circumferential ridge 56 positioned at its distalend. The ridge 56 defines the perimeter 58 of a recessed portion 60having a substantially central aperture 62.

The bellows seal 20 is adapted to accommodate an instrument through itscentral aperture 62. The flexible material enables the aperture 62 toaccommodate instruments of varying sizes while providing a substantiallyfluid and gas tight seal about the instrument, e.g., instruments havingdiameters of from 3 to 15 mm. The size of the aperture in the bellowseal is preferably from 2.5 mm to 3.0 mm (0.10 inches to 0.12 inches).The material of the bellows seal preferably has a durometer value in therange of 35 to 45, and most preferably a durometer value of 40.

When accommodating an instrument through the aperture 62 of the bellowsseal 20, the ridge 56 allows the recessed portion 60 surrounding theaperture 62 to accommodate the instrument while substantiallyencouraging the retention of the circular shape of the aperture.Further, the ridge 56 substantially reduces the chances, for example, ofsealing integrity being compromised by instrument manipulation, or ofthe bellows seal material tearing. The bellows seal 20 as described inthe preferred embodiments herein and illustrated in the accompanyingdrawings, could be any deformable sealing element which includes, forexample, a different geometric aperture configuration.

In operation, referring to FIGS. 1 and 4, the first retainer 16 guidesthe instrument as it is being inserted through the valve assembly 10.The first and second retainers 16, 18 encourage the instrument throughthe valve assembly by assisting the adjacent sealing gasket assembly 36and the bellows seal 20 to accommodate the instrument. The triangularportions 26 of the retainers 16, 18 displace the flexible resilientmaterial of the adjacent sealing gasket assembly 36 and bellows seal 20encouraging easier access for the instrument.

Further, the triangular movable portions 26 of the retainers 16, 18discourage unwanted contact between the instrument, such as a trocarobturator having a sharp tip, and the sealing gasket assembly 36 and thebellows seal 20 by, for example, providing an intermediate surfacebetween the sharp instrument being inserted into the valve assembly 10and the adjacent sealing gasket assembly 36 and bellows seal 20. Bothretainers provide support to the valve assembly such that manipulationof the instrument will not deter the instrument from the desiredpassageway, or compromise the valve assembly's sealing effect.

Although the gasket seal assembly is proximal the bellows seal asdescribed herein and shown in the accompanying drawing of the preferredembodiments, the order may be reversed as desired.

Another embodiment of the valve assembly is shown in FIG. 5. The valveassembly 10 a is similar to the previous embodiment shown in FIG. 1,however, the embodiment shown in FIG. 5 includes, in addition to otherelements contributing to the sealing function of the valve assembly, astabilizer plate 64 at its proximal end. The stabilizer plate 64 has asubstantially central circular aperture 66 therethrough to accommodate asurgical instrument. An integrally molded lip portion 68 extendsoutwardly from the plane of the stabilizer plate further defining theaperture. The stabilizer plate 64 provides rigidity to the overall valveassembly 10 a, and further guides the instrument through a desiredpassageway in the valve assembly 10 a.

A first rectangular retainer 16 is distally adjacent to the stabilizerplate 64. The first rectangular retainer 16 includes a circular bodyportion 24 which fits over the lip portion 68 of the stabilizer plate 64and preferably frictionally engages lip portion 68. The firstrectangular retainer 16 is essentially identical to, and functions asdescribed in the previous embodiment shown in FIG. 1; however, in thepresent embodiment the first rectangular retainer 16 communicates with afirst circular retainer 70.

Referring to FIG. 7, the first circular retainer 70 includes a proximaland a distal ridge 72, 74 positioned about the perimeter and defining agroove 73 therebetween. Similar to the first rectangular retainer 16,the first circular retainer 70 includes a plurality of triangularportions 76 divided by a series of slits 78 which are connected to thedistal ridge 74 by hinge regions 80. The slits 78 extend radially from asubstantially central aperture 82, and the first circular retainer 70 isdimensioned to fit over and preferably frictionally engage the bodyportion 24 of the first rectangular retainer 16. The first rectangularretainer 16 and the first circular retainer 70 are juxtapositioned suchthat the slits 78, 28 of one of the retainers transect the triangularportions 26, 76 of the other retainer. For example, the retainers may bejuxtapositioned such that the slits 78 of the first circular retainer 70overlappingly transect the triangular portions 26 of the firstrectangular retainer 16.

The sealing gasket assembly 36 is positioned distal to the retainers 16,70 and is identical to the sealing gasket assembly 36 described in theprevious embodiment illustrated in FIGS. 1-4 and associates similarlywith the retainer members. In the present embodiment, however, thesealing gasket assembly 36 is positioned proximal to a foam block 84.

The foam block 84 includes a generally rectangular proximal face 86 andtapers generally outwardly from a longitudinal center line to arectangular distal face 88. The foam block 84 includes a circular region90 in its distal end partially extending therethrough to an end wall 92.The end wall 92 includes an aperture extending through the proximal facewhich is defined by three slits 91 converging at a center point 94, andbiased closed by the foam, as shown in FIG. 8. When an instrument ispassed through the aperture the foam accommodates the instrument.Further, the foam block 84 biases the sealing gasket assembly 36 in theclosed position and encourages the sealing gasket assembly 36 toresiliently assume the closed position after an instrument has beenremoved.

A distal retainer 96 is generally circular and is positionable insidethe aperture in the foam block 84. The distal retainer 96 includes acircumferential ridge 98 and a flange 100 extending orthogonally to theplane of the distal retainer 96. Similar to the first circular retainer70, the distal retainer 96 includes a plurality of triangular portions102 attached about the perimeter of the retainer by hinge regions 104. Aplurality of slits 106 define the triangular portions 102 and the slitsextend radially from a central aperture 108.

A second stabilizer 110 is adjacent to the distal retainer 96 and tapersgenerally inwardly towards a longitudinal center line from its proximalend. The proximal end 112 of the second stabilizer mates with the distalretainer 96 and the distal end 114 of the second stabilizer mates withthe second rectangular retainer 18 (described below). The secondstabilizer 110 provides guidance to the instrument as it passes throughthe valve assembly. The first stabilizer plate 64 and the secondstabilizer 110 align the instrument and generally provide support forthe entire valve assembly 10 a.

A second rectangular retainer 18 and a second circular retainer 116 arepositioned distal to the second stabilizer 110. The second retainers 18,116 are essentially identical to the first rectangular and circularretainers 16, 70, are combined in an identical manner, and functionsimilarly.

A bellows seal 20 is positioned distal to the second retainers 18, 116and mates with the second circular retainer 116. The bellows seal 20 isidentical to the bellows seal described in the previous embodimentillustrated in FIG. 1, and functions similarly.

In operation, referring to FIG. 5, a surgical instrument (not shown) maybe inserted at the proximal end of the cannula housing 12. The first andsecond rectangular retainers 16, 18, the sealing gasket assembly 36, andthe bellows seal 20, operate essentially the same as described in theprevious embodiment illustrated in FIG. 1. In the present embodiment,however, the stabilizer plate 64 receives the instrument and guides theinstrument into the valve assembly 10 a. As shown in FIG. 7, as aninstrument passes through the first and second rectangular and circularretainers 16, 70, 18, 116 the triangular plates 26, 76 pivot distallyfrom a longitudinal center line of the retainers. As in the previousembodiment illustrated in FIG. 1, the retainers encourage the instrumentthrough the sealing gasket assembly 36 and the bellows seal 20 by urgingthe flexible materials of the sealing gasket assembly and the bellowsseal to accept the instrument.

Further, the rectangular and circular retainer combination 16, 70, 18,116, are juxtapositioned such that the slits of one retainer transectthe triangular portions of the other, as shown in FIGS. 6 and 7. Thisoverlapping arrangement more effectively discourages unwanted contactbetween the instrument and the other members of the valve assembly. Forexample, the retainers 16, 70, 18, 116 provide an interface between apointed instrument being inserted into the valve assembly and theadjacent sealing gasket assembly or bellow seal, i.e., as the instrumentprojects into the slit 28 of the rectangular retainer 16, 18, thecircular retainer's triangular portions 76 extend between the instrumentand the seal 36, 20.

The instrument passes through the aperture of the foam block 84, whichis biased closed, through deformation and compression of the flexibleresilient foam so as to accommodate the instrument. After the instrumentis removed, the foam block 84 encourages the sealing gasket assembly 36to return to its original position.

The distal retainer 96 is essentially identical to the first circular 70and second circular retainers 116. The distal retainer is designed tofit into the circular region 90 in the foam block. The distal retainer96 operates as the retainers 16, 70 discussed above for discouragingunwanted contact between the instrument and the foam block 84.

Another embodiment of the valve assembly positioned in a cannula housing12 is shown in FIG. 9. The valve assembly 10 b is essentially the sameas the previous valve assembly 10 a shown in FIG. 5; however, theembodiment illustrated in FIG. 9 includes a foam member 118 having twoportions 120, 122, and two single element gasket seals 124 positioneddistal to first retainers 16, 70 and distal to second retainers 18, 116,respectively.

The two portions 120, 122 of the foam member 118 are in side-by-sideabutting relation inside the cannula valve housing 12. The two portions120, 122 are biased towards each other by communicating with the wallsof the cannula valve housing 12. An instrument, however, may passbetween the two portions 120, 122 of the foam member 118 by displacingthe flexible resilient foam.

The two piece resilient foam member 118 biases the adjacent singleelement gasket seal 124 in a closed or rest position. After thewithdrawal of an instrument, the foam member 118 urges the singleelement gasket seal 124 to return to its rest position.

Preferably, both the single element gasket seals 124 include a generallycircular body 128 having a flange 130 at its proximal end extendingradially outwardly. A central passageway 134 is biased closed by theresiliency of the material and is defined by three slits converging at acenter point. As an instrument is passed through the aperture 134defined by the three slits the resilient material accommodates theinstrument. After the instrument has been removed the resilient materialof the single element gasket seals 124 return to its originalconfiguration. The single element gasket seal 124 proximal the foammember 118, for example, may accommodate a partially inserted instrumentwhile the distal single element gasket seal 124 remains in a closed orat rest position.

The first stabilizer plate 64, the first and second rectangularretainers, 16, 18 and the circular retainers, 70, 116 are essentiallythe same as described in the previous embodiment illustrated in FIG. 5and operates similarly.

The valve assembly described in the preferred embodiments andillustrated in the accompanying drawings is preferably capable ofaccommodating instruments varying in diameter from 3 mm to 15 mm, andmost preferably diameters from 5 mm to 12 mm. When inserting theinstrument into the valve assembly as described herein the insertionforce, i.e., the axial force asserted against the instrument to pass theinstrument into and through the valve assembly is preferably kept to aminimum.

For example, preferable insertion forces of approximately no more than 5pounds are desirable for instruments having approximate diameters ofmore than 9 mm. Most preferably, insertion forces of approximately nomore than 4 pounds are desirable for instruments having approximatediameters of between 5 mm and 8 mm.

Moreover, preferable insertion forces of approximately 7 pounds aredesirable for instruments having approximate diameters of 9 mm to 15 mm.Most preferably, insertion forces of approximately no more than 6 poundsare desirable for instruments having approximate diameters of between 10mm and 12 mm.

Referring to FIGS. 10-20, several embodiments of a valve assemblyaccording to the present invention are illustrated. In each embodimentthe valve assembly includes sealing structure having at least threeelements which contribute to the sealing function of the assembly. Thevalve assembly is incorporated into a cannula valve housing 12 having anupper half 12 a and a lower half 12 b attached at the proximal end ofthe cannula 14 which is configured as an elongated tubular member, andalso shown in FIGS. 1, 5 and 9. A tissue gripping apparatus 240 and acannula member 254, as shown in FIGS. 10 and 17, may be attached to thecannula 14. The cannulas proximal end is closest to the surgeon and itsdistal end is opposite the proximal end. Both the distal and proximalends of the cannula are referred to herein for reference.

The valve assemblies shown in FIGS. 10-20 provide a substantial sealbetween a body cavity of a patient and the outside atmosphere before andafter an instrument is inserted through the cannula valve housing 12.Moreover, each of the embodiments of the valve assemblies are capable ofaccommodating instruments of varying diameters, e.g., from 3 mm to 15mm, by providing a substantial gas and fluid tight seal before and afterinstrument insertion. This instrument accommodating flexibility of thepresent valve assemblies greatly facilitates endoscopic surgery where avariety of instruments having differing diameters are often neededduring a single surgical procedure.

Referring to FIGS. 10-14, a preferred embodiment of a valve assembly 140includes a two piece housing assembly 142, sealing structure comprisinga sealing gasket assembly 144 having first and second elements, andsealing structure further comprising a third sealing element embodied asa conical seal 148, conical retainers 150, square retainers 146, astabilizer plate 152, and a fastening ring 154.

The sealing gasket assembly 144 of the valve assembly 140 is positionedin the housing assembly 142. The sealing gasket assembly 144 may includecharacteristics similar to sealing gasket assembly 36 described aboveand shown in FIGS. 1-5.

Specifically, the sealing gasket assembly 144 preferably includesidentical first and second overlapping sealing elements 156, 158 made ofa flexible resilient material. Preferably, both the first and secondsealing elements 156, 158 include a circumferential ridge 160 and a wall162 enclosed by the ridge 160. Each wall 162 includes a semi-circularopening 164.

Each of sealing elements 156, 158 includes a pair of radially opposedholes 166, as best seen in FIG. 11. The holes 166 mate with the pins 168of the cylindrical body portion 170 of the two piece housing assembly142. Although the sealing gasket assembly 144 is shown being attached tothe housing assembly 142 by pins 168, other methods may be used, suchas, for example, adhesives.

The flexible nature of the elements 160 of the sealing gasket assembly144 enable the elements 160 to mate with one another by stretching oneelement 160 over the other. The elements 160 cooperate by positioningthe semi-circular opening 164 in each element 160 radially opposite eachother. Thus, the first and second sealing elements 160 mate inoverlapping relation such that the wall 162 of one element overlaps thesemi-circular opening 164 of the other element.

The overlapping sealing elements 160 define a sealable passagewaytherethrough. The flexible nature of the walls 162 allow the sealinggasket assembly 144 to deformably accommodate an instrument passedtherethrough. Moreover, the walls 162 resiliently return to theiroriginal position after removal of an instrument. Thus, the overlappingrelation of the elements of the sealing gasket assembly 144 provides asubstantially fluid tight seal before instrument insertion and helps todiscourage fluid passage around an instrument passed through the sealinggasket assembly 144.

The sealing gasket shown FIGS. 10-14, as with the previous sealinggasket shown in FIGS. 1-5, includes flexibly resilient material allowingthe sealing gasket assembly 36 to accommodate instruments of varyingsizes, e.g., diameters of from 3 mm to 15 mm. The sealing gasketassembly 144 is preferably made of a flexible material having adurometer valve in the range of 25-35, and most preferably a durometervalve of 30.

To facilitate and ensure that the fluid tight seal is reestablished uponinstrument removal, it is preferred that walls 162 of the elements 160be placed under tension, thereby creating a tautness which furtherbiases walls 162 toward their initial overlapping, abutting relation.

The tensioning of the overlapping sealing elements 160 furtherencourages the overlapping elements 160 to surround an instrument passedtherethrough. The overlapping elements 160 are biased in an overlappingabutting relation to substantially discourage gas and fluid leakagethrough the valve assembly. When an instrument is inserted through thepassageway, the flexible overlapping elements 160 accommodate andsubstantially surround the outer surface of the instrument. The flexiblenature of the overlapping elements surround the instrument providingsubstantial gas and fluid sealing.

The tension is created in the walls 162 of the sealing gasket 144 bystretching each element 160 onto the pins 168 of the housing assembly142. Each hole 166 mates with the corresponding pin 168 of the housingassembly 142. The pin 168 placement requires that the elements 160 besubstantially stretched to mate the holes 166 with the pins 168. Thissecures the elements to the cylindrical body portion of the housingassembly 142 while creating and maintaining the desired wall 162tension. As shown in FIG. 12, flexible resilient walls accommodate aninstrument 37 by resiliently deforming to enable the instrument 37 topass therethrough. Fluid flow is discouraged around the instrument bythe flexible elements 160 substantially surrounding the instrument 37 asit is passed therethrough. The tensioning of the overlapping elements160 further provides radial tensioning of the overlapping elements 160on the surface of the instrument. The contact between the overlappingelements 160 and the surface of the instrument helps to prevent theunwanted egress of fluids when an instrument 37 is passed through thevalve assembly.

Upon removal of instrument 37, resiliently deformable sealing gasketassembly 144 returns to its initial position, thereby reestablishing asubstantially fluid tight seal with the instrument 37 removed.

The valve assembly 140 may also include structure for inhibitingunwanted contact between an instrument being inserted and sealingstructure, in this case, the sealing gasket assembly 144. A preferredembodiment of such structure is shown in FIGS. 10-14 as first and secondsquare retainers 146. Although, the first and second retainers 146 areshown as square, other configurations are also contemplated, such as,circular. The retainers may be somewhat similar to the retainers 16 and18 shown in FIG. 5 and described above.

Each of the square retainers 146 of the present embodiment shown inFIGS. 10-14 are essentially identical to each other and include a bodyportion 171 having a series of triangularly shaped portions 172 defininga series of slits 174 therebetween. As best seen in FIG. 11, preferably,a plurality of triangularly shaped movable portions 172 are divided by aseries of slits 174 and are attached to the body portion 171 byhinge-like regions 176. The triangularly shaped portions 172 arepositioned radially about a substantially central axis. The slits 174 ofthe one of the retainers 146 bisect the triangular portions 172 of theother retainer 146. The square retainers 146 are preferably formed of asuitable synthetic resin or plastic, such as polypropylene.

The square retainers 146 are juxtapositioned such that the slits of oneof the retainers transect the triangular portions 172 of the otherretainer to provide enhanced protection of the sealing gasket assembly144 from an instrument inserted into the valve assembly 140.

As the instrument passes through the square retainers 146, thetriangular portions 172 accommodate the instrument by moving distallyexposing the split 174 therebetween to the entering instrument. However,the adjacent sealing gasket assembly 144 remains uninjured by theentering instrument because the overlapping square retainers 146distally positioned with respect to triangular portions 172 discouragethe instrument from contacting the sealing gasket assembly 144. Contactis discouraged because the square retainers 146 are positioned betweenthe entering instrument and the sealing gasket assembly 144, and thejuxtapositioning of the square retainers 146 provide a substantiallycontinuous surface protecting the sealing gasket assembly 144.

The valve assembly 140 may also include structure for stabilizing theinstrument when the instrument is passed through the valve assembly 140.An embodiment of such structure in accordance with the present inventionis shown in FIGS. 10-14 as a stabilizer plate positioned proximally ofthe square retainer plates 146.

The stabilizer plate 152 has some similarities to the stabilizer plate64 shown in FIG. 5. The stabilizer plate 152 shown in FIGS. 10-14 isgenerally square in shape and includes a body portion 178 defining asubstantially central circular aperture 180 therethrough to accommodatea surgical instrument. The stabilizer plate 64 provides rigidity to theoverall valve assembly 140, and further guides an instrument through adesired passageway in the valve assembly 140.

The valve assembly 140 may also include sealing structure comprising athird sealing element for substantially sealing the valve assembly afteran instrument is passed therethrough. An embodiment of such a thirdsealing element in accordance with the present invention is shown inFIGS. 10 and 12-14 as a conical seal 148 positioned distally adjacent toconical retainers 150 and constructed of a suitable flexible resilientmaterial.

The conical seal 148 includes a body portion 182 having a taperedsection 184 which has a substantially conical configuration and asubstantially central hole 186 therethrough. The body portion 182further includes a circumferential ridge 188 positioned proximal to thetapered section 184. The ridge 188 is substantially integral with thebody portion 182 and extends radially outwardly from the body portion182.

The conical seal 148 is preferably formed of an elastomeric materialsuch as, for example, natural rubber.

The elastomeric material of the conical seal 148 allows the conical seal148 to accommodate instruments of varying diameters through its centralaperture 186. The elastomeric tapered section 184 of the conical seal148 deforms and flexes for sealing about the instrument passedtherethrough. As the instrument is passed through the hole 186 of thetapered section 184, the elastomeric material of the conical sectiondeforms to accommodate the instrument, as shown in FIG. 14. Thedeformation of the tapered section 184 is desirable for substantiallysealing about the instrument.

The flexible material of the tapered section 184 enables the hole 186 toaccommodate instruments of varying sizes while providing a substantiallyfluid and gas tight seal about the instrument, e.g., instruments havingdiameters of from 3 mm to 15 mm. The size of the hole 186 in the conicalseal 148 is preferably from 2.5 mm to 3.0 mm (0.10 inches to 0.12inches). The material of the conical seal 148 preferably has a durometervalue in the range of 30 to 45, and most preferably a durometer value of40.

The conical configuration, or frustoconical shape of the conical seal148 favorably influences the amount of insertion force required to passan instrument therethrough. The conical shape of the seal 148 deformablyadapts to the inserted instrument, thus, reduced insertion forces on theinstrument are required.

The valve assembly 140 may also include another embodiment of astructure for inhibiting unwanted contact between an instrument beinginserted and sealing structure, in this case, the conical seal 148. Apreferred embodiment of such structure is shown in FIGS. 10, and 12-14,as conical retainers 150 which are essentially identical. Each conicalretainer 150 includes a body portion 190 having a tapered portion 192being generally conically shaped. The tapered portion 192 includes aseries of triangularly shaped sections 194 defining a series of slits196 therebetween. The triangularly shaped sections 194 are positionedradially about a substantially central axis. The slits 196 of oneconical retainer 150 bisect the triangular sections 194 of the otherconical retainer 150. The conical retainers 150 are preferably formed ofa suitable synthetic resin or plastic, such as polypropylene.

As best seen in FIG. 12, preferably, a plurality of triangularly shapedmovable portions 194 are divided by a series of slits 196 and areattached to the perimeter 198 of the conical retainers 150 by hingeregions 152. The slits 196 extend radially outward from central aperture200 of the conical retainers 150. The conical retainers 150 arejuxtapositioned such that the slits 196 of one of the retainers transectthe triangular portions 194 of the other retainer, in a similar manneras with the square retainers 146.

When an instrument is passed through conical retainers 150, therebyentering the conical seal 148, the triangular portions 194 discourageunwanted contact with the conical seal 148. Contact is discouraged in asimilar manner as with the square retainers 146 discussed above.

The housing assembly 142 of the valve assembly 140 shown in FIGS. 10-14is a preferred embodiment of a structure for tensioning overlappingfirst and second elements of the sealing gasket assembly 144. Thehousing assembly 142 comprises a cylindrical body portion 170 having apassageway 204 therethrough. The cylindrical body portion 170 may act asa frame for receiving the sealing gasket assembly 144. The housingassembly 142 further includes a housing end cap 208 removable positionedproximal to the cylindrical body portion 170, and a fastening ring 154positioned distal to the body portion 170. The proximal end of thecylindrical body portion 170 of the housing assembly 142 includes outerand inner ridges 210, 212, both extending proximally with respect to thecylindrical body portion 170. The ridges 210, 212 define a groove 214therebetween that is dimensioned and configured for mating with thesealing gasket assembly 144. The ridge 210, 212 also includes a groove216 circumscribing an inner surface of the outer ridge 210 which is alsodimensioned and configured to receive the sealing gasket assembly 144.

Further, two pins 168 extend proximally from the cylindrical bodyportion 170. The two pin 168 are passed through the mating holes 166 inthe sealing gasket assembly 144 to provide the desired tensioning of thegasket sealing assembly 144, as well as, to fixedly position the sealinggasket 144 in the housing assembly 144.

The end cap 218 of the housing assembly 142 includes inner and outer220, 222 concentric ridges defining a groove 224 therebetween. Thegroove 224 is dimensioned and configured to receive the proximal end ofthe sealing gasket assembly 144. Once the sealing gasket assembly 144 isseated therein, the housing end cap 218 can be mated with thecylindrical body portion 170 of the housing assembly 142. The housingend cap 218 and the cylindrical body porion 170 of the housing assembly142 can be mated, for example, by welding, or adhesive, or by othermethods known in the art.

As best seen in FIG. 11, the end cap 218 of the housing assembly 142further includes a proximally extending rectangular portion 226. Therectangular portion 226 of the housing end cap 218 has a generallyL-shaped inner portion having a proximally extending ridge 228. Theinner side of the rectangular portion 226 is dimensioned and configuredto removable receive the square retainers 146 and the stabilizer plate152 providing positive placement of the retainers 146 and stabilizingplate 152 therein.

The cylindrical portion 170 of the housing assembly 142 further includesat its distal end, concentric inner and outer flanges 230 and 232defining a channel 234 therebetween. The channel 234 is dimensioned andconfigured to accommodate the conical retainers 150, conical seal 148,and the fastening ring 154 in mating relation.

The fastening ring 154 is positioned distal to the conical seal 148. Thefastening ring 154 includes a circular body portion 236 having anaperture 238 therethrough. The aperture 238 has an inner diameterdimensioned to fit over the tapered portion 184 of the conical seal 148and abut ridge 188. The fastening ring 154 mates with the channel 234 tohold the conical seal 148 and the conical retainers 150 in place. Thefastening ring 154 may be attached to the housing assembly 142 by, forexample, welding or adhesive, or by other methods known in the art.

It is envisioned that the conical sealing member 148 and the sealinggasket assembly 144 can be positioned proximal or distal to each otherand be equally effective.

Referring to FIGS. 10 and 17, according to the present invention, atissue gripping apparatus 240 is used with the elongated tubularlyshaped cannula 14. The tissue gripping apparatus 240 includes acylindrical body portion 242, and a flexible element 246 having aplurality of substantially parallel articulated arms 248. Each of thearms 248 have a hinge 250 located proximal to a midpoint of eachrespective arm 248, preferably each hinge 250 is substantially the samedistance from the midpoint of the respective arms 248.

The cylindrical body portion 242 may be constructed, preferably, of asubstantially resilient flexible material such that the cylindrical bodyportion 242 can frictionally engage the elongated tubular cannula 14.The frictional engagement of the cylindrical body portion 242 with thecannula 14 allows the body portion 242 to be slidable positionable alongthe canula 14. The body portion 242 is moved distally to fully deploythe tissue gripping apparatus 240; that is, when the articulated arms248 are in an extended position bending at their hinges 250.

An actuation member 252 is situated at a proximal end of the cylindricalbody portion 242. The actuation member 252 allows a surgeon to easilymove the cylindrical body portion 242 distally to deploy the articulatedarms 248. The articulated arms 248 are in a preferred deployed positionwhen the arms 248 proximal the hinge 250 are in a substantiallyperpendicular orientation relative to the body portion 242. Thisperpendicular orientation ensures optimum retention of the surgicalapparatus in, for example, the abdomen by securingly engaging the innerwall of the abdominal cavity. other actuation systems wherebycylindrical body portion 242 may be moved distally to deploy arms 248may, of course, be employed.

Referring to FIGS. 10 and 17, a cannula member 254 is provided for usewith a tubular member, such as the cylindrical body portion 242 of thetissue gripping apparatus 240, or a cannula or similar device to deterthe escape of gases from the body cavity passed the cannula insertedtherein and to provide support to the cannula inserted in the bodycavity. For example, gasses may escape when a surgeon is engaging inendoscopic or laparoscopic procedures requiring insufflation of the bodycavity or the cannula may undesirably slant making instrument insertiondifficult.

An embodiment of a cannula member 254 for use with a cannula 24 andworking in concert with the tissue gripping apparatus 240 is shown inFIGS. 10 and 17. The illustrated cylindrical cannula member 254 isslidably positioned about the body portion 242 of the tissue grippingapparatus 240. The cannula member 254 includes a body portion 256 havingconcentric inner and outer flanges 258, 260. The flange 258 and 260 arepositionable against a patient's body to provide sealing and stabilizingproperties.

The cannula member may be, for example, constructed of an elastomericmaterial, which is preferably an elastomer commercially available underthe trademark “SANTOPRENE”, manufactured by Monsanto.

The cannula member 254 is contemplated to be rigid enough such that theflanges 258, 260 of the cannula member can be placed against a patientsskin to enhance stabilization of the cannula 14 positioned through thebody wall of the patient. The cannula's 14 increased stability providesgreater ease of entry into the cannula 14 by the surgeon, as well as,moderating angular movement of the cannula 14. This increased stabilitydecreases the likelihood of irritation or trauma around the entry siteof the cannula 14 into the body cavity.

Although the cannula member moderates angular movement of the cannula24, some angular movement of the cannula 24 is likely and may bedesirable. Cannula member 254 is designed to remain in substantialcontact with the patient's body while accommodating the cannula 14 invarying angular positions with respect to the patient's body.

In operation, the cannula member 254 as shown in FIGS. 10 and 17 is usedwith the cannula 14 and in concert with the tissue gripping apparatus240. Typically, a trocar device including, for example, an obturator(not shown) and a cannula 14 is employed to puncture the skin andprovide access to the surgical area. A pointed obturator may be used forpenetrating the skin to extend the trocar beyond the body wall to thesurgical site. Alternatively, an incision may be made using a scalpel orsimilar device before inserting a blunt obturator through the incision.When either obturator is removed, the cannula remains in place tomaintain access to the surgical site, and several incisions may be madeto provide numerous access ports to the surgical objective.

Once the cannula(s) are in place, the tissue gripping apparatus 240 isactuated into a deployed position by moving the actuation member 252distally. The articulated parallel arms 248 move outwardly as hinges 250extend the parallel arms 248 to a fully deployed position. The locationof the hinge 250 on the articulated parallel arms 248 allows the portionof the arms 248 proximal the hinge 250 to be substantially perpendicularto the tubular portion 242 of the tissue gripping apparatus 240. Thecannula 14 is thereby secured in the incision by the extendedarticulated parallel arms 248 of the tissue gripping apparatus 240.

The cannula member 254 is then urged towards the patient's body bymanually advancing the cannula member 254 distally until the inner andouter flanges contact the patient's skin. The outer and inner 258, 260contact the patient's skin providing a substantial gas seal flanges 258,260 for maintaining insufflation pressure within the body cavity, andstabilizing the cannula 14 in the incision.

The cannula member 254 is designed to remain in substantial contact witha patient's body while accommodating the cannula 14 in varying angularpositions with respect to a patient's body. More specifically, thecannula member 254 is at least partially constructed of flexiblematerial which allows for angular juxtapositioning of the cannula 14with respect to a patient's body while maintaining a substantialrelationship between the flanges of the cannula member 254 and apatient's body.

The cannula member 254 has adequate rigidity for providing stabilizationof the cannula 14. The rigid nature of the cannula member 254 enhancessupport of the cannula 14 positioned through an incision in the bodycavity. The cannula's 14 increased stability provides greater ease ofentry into the cannula 14 by the surgeon, as well as, moderating angularmovement of the cannula 14. This increased stability decreases thelikelihood of irritation or trauma around the entry cite of the cannulainto the body cavity.

Referring to FIGS. 12-14, the valve assembly 140 operates as describedbelow. A surgical instrument may be inserted at the proximal end of thecannula housing 12. As the instrument 37 is passed through the valveassembly 140, the stabilizer plate 152 receives the instrument 37 andguides the instrument 37 into the valve assembly 140, as shown in FIG.12.

As an instrument 37 passes through the retainers 146 the triangularplates 172 pivot distally from a longitudinal center line of theretainers 146. The overlapping retainers 146 encourage the instrumentthrough the valve assembly 140 by assisting the sealing gasket assembly144 to accommodate the instrument 37. The triangular portions 172 of theretainers 146 displace the flexible resilient material of the adjacentsealing gasket assembly 144 encouraging easier access for the instrument37.

Further, the triangular movable portions 172 of the retainers 146discourage unwanted contact between the instrument 37, such as a trocarobturator having a sharp tip, and the sealing gasket assembly 144. Morespecifically, the retainers 146 provide an intermediate surface betweena sharp instrument being inserted into the valve assembly 40 and theadjacent sealing gasket assembly 140. Both retainers also providesupport to the valve assembly 140 such that manipulation of theinstrument 37 will not deter the instrument from the desired passageway,or compromise the valve assembly's 140 sealing effect.

Further, the square retainers 146 are juxtapositioned such that theslits of one retainer 146 transect the triangular portions 172 of theother, as shown in FIG. 11. This overlapping arrangement moreeffectively discourages unwanted contact between the instrument 37 andthe other members of the valve assembly, in this case the sealing gasketassembly 144.

Referring to FIG. 12, as the instrument 37 continues through the valveassembly 140 it enters the housing assembly 142 and engages the sealinggasket assembly 144. The sealing gasket assembly 144 accommodates theinstrument 37 in the operable passageway defined by the overlappingelements 160. The overlapping elements 160 substantially surround theouter surface of the instrument 37 and discourage fluids and gasses fromescaping from around the instrument 37.

Referring to FIGS. 13 and 14, as the instrument 37 extends through thedistal end of the housing assembly 142, it engages the conical retainers150 and the conical seal 148. As with the square retainer 146 describedabove, the triangular portions 194 of the conical retainers 150discourage unwanted contact with the conical seal 148. Contact isdiscouraged because the conical retainers 150 are positioned between theentering instrument 37 and the conical seal 148.

Further, similarly to the square retainers 146 described above, as aninstrument 37 passes through the conical retainers 150 the triangularplates 194 pivot distally from a longitudinal center line of theretainers 150. The overlapping retainers 150 encourage the instrument 37through the conical seal 148 by assisting the conical seal 148 toaccommodate the instrument 37. The triangular portions 194 of theretainers 150 displace the flexible resilient material of the adjacentconical seal 148 encouraging easier access for the instrument 37.

As the instrument 37 is passed through the central aperture 186 of theconical seal 148 the elastomeric material of the tapered section 184deforms and flexes to accommodate the instrument 37. The flexible natureof the conical seal 148 provides sealing about the instrument 37 passedtherethrough.

After the surgery is completed, the surgical instrument 37 may bewithdrawn from the cannula 14. The valve assembly 140 providessubstantial fluid and gas tight sealing before and after the instrument37 is withdrawn.

To remove the cannula 14, the cannula member 254 may first be manuallymoved proximally, or the cannula member 254 may also be moved proximallyby releasing the tissue gripping apparatus 240. By either method, thedistal movement of the cannula member 254 removes the flanges 258, 260from contact with the patient's skin.

The tissue gripping apparatus 240 may be removed by releasing thearticulated parallel arms 248 of the tissue gripping apparatus 240. Thearticulated parallel 248 arms are returned to their at rest position bymoving the actuation member 252 proximally.

After the tissue gripping apparatus 240 is released, the entire tissuegripping apparatus 240, and cannula 14 may be withdrawn from theincision.

Another embodiment of a valve assembly positioned in a cannula housing12 is shown in FIGS. 15 and 16. The valve assembly 262 is essentiallyidentical to the previous valve assembly 140 shown in FIGS. 10-14,however, the embodiment illustrated in FIGS. 15 and 16 includes sealingstructure having a fourth sealing element embodied as wiper means orspitback seal 264. The similar elements between the embodiments shown inFIGS. 10-14 and FIGS. 15 and 16 function in a similar manner to thevalve assembly 140 embodiment shown in FIGS. 10-14 and described above.However, the spitback seal 264 of the embodiment shown in FIGS. 15 and16 includes characteristics as described below.

The spitback seal 264 is preferably positioned between a rectangularretainer 146 and a stabilizing plate 152. The spitback seal 264 may alsobe positioned at other locations, such as, distal to the sealing gasketassembly 144.

Typically, as the instrument 37 is removed from the valve assembly 262,fluids may be on the surface of the instrument and are removed with theinstrument 37. These unwanted fluids can be disruptive to the surgeon.To substantially discourage such fluids from egressing from the valveassembly 262 in this manner, a spitback seal 264 is provided.

The spitback seal 264, preferably, has a generally square shape, but maybe other configurations, such as rectangular. The spitback seal 264 isconstructed at least partially of a deformable material defining asubstantially central aperture 266. The substantially central apertureaccommodates the instrument 37, as seen in FIG. 16, such that thedeformable material defining the aperture 266 contacts the outer surfaceof the instrument 37 substantially removing fluids therefrom.

More specifically, as the instrument 37 is withdrawn from the valveassembly 262, the deformable material of the spitback seal 264 whichdefines the aperture 266 therethrough substantially engages the outersurface of the instrument 37. The flexible nature of the spitback seal264 may deform in a proximal direction as shown in FIG. 16. Thisdeformability substantially enables the material of the spitback seal264 defining the aperture 266 to remove fluids clinging to the surfaceof the instrument 37 as the instrument 37 is removed from the valveassembly 262. Thus, fluids are discouraged from exiting the valveassembly 262 as the instrument 37 is removed therefrom.

Another embodiment of a valve assembly 270 positioned in a cannulahousing 12 is shown in FIGS. 17-20. The valve assembly 270 may includesimilarities to the previous valve assembly 140 shown in FIGS. 10-14.

Referring to FIG. 17, the valve assembly 270 includes stabilizer plate152, square retainers 146, sealing gasket assembly 144, and housingassembly 142, which are essentially identical to those shown in FIGS.10-14 as part of valve assembly 140 described above.

The valve assembly 270 further includes first and second circularretainers 272 which are essentially identical. Each retainer 272includes a body portion 274 having a plurality of movable triangularportions 276 movable attached to the body portion 274. Both circularretainers 272 the plurality of triangular portions 276 divided by aseries of slits 278. The slits 278 extend radially from a substantiallycentral aperture 280. The circular retainers 272 are juxtapositionedsuch that the slits 278 of one of the retainers 272 transect thetriangular portions 276 of the other retainer 272.

The valve assembly 270 further includes sealing structure comprising afifth sealing element embodied as a bellows seal 20 for substantiallysealing the valve assembly after an instrument is passed therethrough.The bellows seal 20 is identical to the bellows seal 20 shown in FIGS. 1and 5. The bellows seal 20, shown in FIGS. 17-20 is positioned distal tothe retainers 272. The bellows seal 20 mates with the circular retainer272 in a similar manner as the bellows seal 20 mates with the secondrectangular retainer 18 and second circular retainer 116 shown in FIG.5.

The bellows seal 20 and the circular retainers 272 are positioned in thechannel 234 of the housing 142 in a similar manner as with the conicalseal 148 and conical retainers 150 shown in FIGS. 10-14. Further thefastening ring 154 secures the bellows seal 20 and the circularretainers 272 in the housing assembly 142 in a similar manner as withthe conical seal 148 and conical retainers 150 shown in FIGS. 10-14.

In operation, referring to FIGS. 18 and 19, as an instrument passesthrough the square retainers 146, and the gasket seal 144 housed in thehousing assembly 142, the retainers 146 and the gasket seal 144accommodate the instrument 37 in essentially the same manner as in valveassembly 140 described above and shown in FIGS. 10-14.

Referring to FIG. 20, the instrument engages the first and secondcircular retainers 272 and the bellows seal 20 in a manner which may besimilar to the retainers 18, and 116 and the bellows seal 20 shown inFIG. 5. As shown in FIG. 20, the overlapping circular retainers 272encourage the instrument 37 through the valve assembly 270 by assistingthe bellows seal 20 to accommodate the instrument 37. Further, thetriangular movable portions 276 of the circular retainers 272 discourageunwanted contact between the instrument 37 and the sealing gasketassembly 144 and the bellows seal 20.

While the invention has been particularly shown, and described withreference to the preferred embodiments, it will be understood by thoseskilled in the art that various modifications and changes in form anddetail may be made therein without departing from the scope and spiritof the invention. Accordingly, modifications such as those suggestedabove, but not limited thereto, are to be considered within the scope ofthe invention.

1. A valve assembly for maintaining a substantial fluid tight sealbetween an internal portion of a patient's body and an outsideatmosphere during introduction of a surgical instrument into thepatient's body which comprises: sealing structure including at least onesealing gasket assembly having first and second overlapping elementseach defining an opening arranged so that, said elements form asubstantial gas and fluid tight seal prior to inserting an instrumenttherethrough, said elements being further constructed of a flexiblematerial to allow passage of said instrument through said openings andprovide substantial sealing about said instrument; and means fortensioning said first and second overlapping elements of said sealinggasket such that said overlapping elements are biased in a closedposition providing a gas and fluid tight seal prior to instrumentinsertion therethrough.
 2. A valve assembly according to claim 1,wherein said tensioning means includes a frame for receiving andtensioning first and second elements of said sealing gasket assembly. 3.A valve assembly according to claim 1 further comprising a housingstructure for housing said tensioning means such that said sealinggasket is positionable substantially within said housing.
 4. A valveassembly according to claim 1 further comprising means for inhibitingcontact of said instrument sealing structure.
 5. A valve assemblyaccording to claim 4, wherein said means for inhibiting defines apassageway for receiving said instrument and includes at least onemovable portion such that said movable portion inhibits contact betweensaid instrument and said adjacent sealing structure.
 6. A valve assemblyaccording to claim 1 wherein said sealing structure further comprises athird sealing element having an at least partially tapered body portionbeing at least partially of a flexible material and defining asubstantially central aperture for accommodating said instrument.
 7. Avalve assembly according to claim 6 wherein said tapered body of saidthird sealing element is generally conical in configuration.
 8. A valveassembly according to claim 1 further comprising means for stabilizingsaid instrument when said instrument is positioned at least partially insaid valve assembly.
 9. A valve assembly according to claim 8 whereinsaid stabilizing means is positioned adjacent an entrance of said valveassembly such that said instrument is substantially guided by saidstabilizing means.
 10. A valve assembly according to claim 1, furthercomprising wiper means for substantially removing fluids from an outersurface of said instrument, said wiper means including a body portionconstructed at least partially of a deformable material and defining asubstantially central aperture for accommodating said instrument.
 11. Acannula assembly for a trocar assembly, said cannula assembly adapted tomaintain a substantial seal between a cavity inside of a patient's bodyand an outside atmosphere, said cannula assembly comprising: a tubularbody portion; a cannula valve housing positioned at a proximal end ofsaid tubular body portion of said cannula; sealing structure comprisingat least one sealing gasket assembly having first and second overlappingelements each defining an opening arranged so that, said elements form asubstantial fluid and gas tight seal prior to inserting an instrumenttherethrough, said elements being constructed of a flexible material toallow passage of said instrument through said openings; and said sealinggasket assembly being couplable to a frame such that said first andsecond overlapping elements are tensioned for biasing said overlappingelements in a closed position prior to an instrument passingtherethrough.
 12. A cannula assembly according to claim 11, wherein saidsealing structure further comprises at least one deformable thirdsealing element fabricated from a flexibly resilient material anddefining a substantially central aperture for accommodating saidinstrument.
 13. A cannula assembly according to claim 11, furthercomprising at least one retainer element having at least one movableportion, said retainer element having passageway to receive saidinstrument, such that said movable portion inhibits contact between saidinstrument and said sealing structure.
 14. A cannula assembly accordingto claim 11 further comprising at least one retainer element defining asubstantially central aperture, said retainer element including at leastone movable portion extending from a perimeter of said retainer elementtowards a longitudinal axis of said retainer element, said at least onemovable portion defining at least one slit, said retainer elementreceiving said instrument while said movable portion inhibits contactbetween said instrument and said sealing structure.
 15. A cannulaassembly according to claim 11 further comprising: an outer sleeveslidably positioned about said tubular body portion of said cannula; aplurality of articulated arm members positioned at a distal end of saidouter sleeve, at least one hinge positioned proximal of a midpoint ofeach of said arms, said articulated arms being manipulable between anextended position and a non-extended position such that a portion ofeach arm proximal each of said hinges is positioned substantiallyperpendicular relative to said tubular body portion when said arms arein said extended position; and cannula member including a substantiallycircular member longitudinally positionable about said tubular bodyportion, said substantially circular member including a flange at adistal end thereof, said flange being positionable against a patient'sbody such that said flange forms a substantially continuous seal againstthe skin for providing enhanced stabilization of said cannula positionedwithin said body cavity.
 16. A cannula according to claim 15, whereinsaid articulated arms are integral with said outer sleeve.
 17. A sealassembly which comprises: a frame; at least one sealing gasket assemblyconstructed of a flexible material and mounted to said frame, thesealing gasket assembly including: a first sealing element defining afirst semicircular opening and having a first wall; and a second sealingelement defining a second semicircular opening and having a second wall;and at least one retainer element defining a substantially centralaperture, said retainer element having adjacent movable portionsconfigured and dimensioned to inhibit contact between an instrument andsaid at least one sealing gasket assembly upon insertion of theinstrument through the sealing gasket assembly; the at least one sealinggasket assembly being mounted so that the first and second walls overlapand define a substantial gas and fluid tight seal in the absence of theinstrument inserted through the semicircular openings and so that thefirst and second walls are separable to allow the passage of theinstrument through the semicircular openings.
 18. A valve assemblyaccording to claim 17 wherein said frame includes at least twoattachment members to engage and tension said first and second walls.19. A seal assembly according to claim 17 wherein the frame tensions thefirst and second walls by resiliently stretching the first and secondwalls.
 20. A seal assembly according to claim 17 wherein said at leastone sealing gasket assembly is constructed from a flexible materialhaving a durometer value between about 25 and
 35. 21. A seal assemblyaccording to claim 17 further comprising a housing structure whichsurrounds and encloses said frame.
 22. A seal assembly according toclaim 17 wherein at least one of said plurality of movable portionspivots distally from a substantially central longitudinal axis of saidseal assembly.
 23. A seal assembly according to claim 17 wherein a forceis required to insert an instrument having a diameter of no more thanabout 15 mm through and semi-circular openings of said at least onesealing gasket assembly and said force is not more than about 7 pounds.24. A seal assembly according to claim 17, wherein the plurality ofmovable portions are disposed along a plane in the absence of aninstrument being inserted therethrough.
 25. A seal assembly according toclaim 17 which further comprises a plurality of retainer elements, eachof said plurality of retainer elements defining a substantially centralaperture, and including plurality of adjacent movable portionsconfigured and dimensioned to inhibit contact between the instrument andsaid at least one sealing gasket assembly upon insertion of theinstrument through the sealing gasket assembly, wherein said adjacentmovable portions are each defined by a pair of slits extending radiallyat least partially between said adjacent movable portions from saidsubstantially central aperture.
 26. A seal assembly according to claim25, wherein the plurality of retainer elements comprises two retainerelements which are juxtapositioned relative each other.
 27. A sealassembly according to claim 26, wherein said two retainer elements arepositioned relative each other such that said plurality of movableportions of one of said two retainer elements are axially offsetrelative to the plurality of movable portions of the other of said tworetainer elements.
 28. A seal assembly according to claim 17, whereinsaid plurality of movable portions are formed of plastic.
 29. A sealassembly according to claim 17, further comprising a plurality ofretainer elements, each of said plurality of retainer elements defininga substantially central aperture, and including a plurality of adjacentmovable portions configured and dimensioned to inhibit contact betweenthe instrument and said at least one sealing gasket assembly uponinsertion of the instrument through the sealing gasket assembly, whereinsaid adjacent movable portions are each defined by a pair of slitsextending radially at least partially between said adjacent movableportions from said substantially central aperture, said plurality ofretainers being positioned such that said plurality of adjacent movableportions of a first of said plurality of retainer elements are inoverlapping juxtaposed relation with said plurality of adjacent movableportions of a second of said plurality of retainer elements.
 30. A sealassembly according to claim 29 wherein each of said plurality ofadjacent movable portions of said plurality of retainer elements istriangular shaped, and further wherein at least one of said slits whichdefines a triangular shaped movable portion of said first retainerelement transects the triangle shaped movable portion of another of saidsecond retainer element.